3D PIC-MC simulation of anode effects in dual magnetron discharges

Development of industrial plasma coaters regarding throughput and precision necessitate the utilization of appropriate modeling tools. Thus, a parallel computing simulation environment for gas flows and gas discharges has been implemented at Fraunhofer IST. The simulation environment, called PIC-MC is based upon the particle-in-cell Monte Carlo approach. While many PIC-MC studies reported in literature are restricted to simplified two-dimensional geometries, we put much effort in enabling three-dimensional simulation studies by optimization of the underlying field solver modules in particular. This involves the parallelization of the magnetic field solver based on the boundary element method which is now capable of handling industrial sized magnetron array arrangements. Furthermore the scaling behavior of the parallel electric field solver based on the Taylor extrapolation method has been improved. With recent software optimizations and better availability of parallel high performance computing hardware, 3D magnetron discharge simulations are now becoming feasible at low and moderate power density. In this work we present PIC-MC simulation results for a dual magnetron discharge set-up with anode bars. We especially investigate the discharge dynamic and the resulting electron flux for magnetically shielded anodes. By applying our simulation tool we can reproduce experimentally observed features such as electron flux constrictions forming local "hot spots" on the anode bars. The PIC-MC simulation allows for better understanding of this phenomenon which could severely damage the sputter equipment.